Knotmeter

ABSTRACT

The present invention relates to a &#39;&#39;&#39;&#39;speed indicator or knotmeter,&#39;&#39;&#39;&#39; for indicating the speed of a boat; and more particularly, relates to a knotmeter &#39;&#39;&#39;&#39;sending unit&#39;&#39;&#39;&#39; that may be easily and quickly withdrawn from and inserted through the hull of a boat. The ease with which the sending unit may be handled encourages preventive maintenance, and facilitates repair when this is necessary.

United States Patent 1191 Phillips KNOTMETER [76] Inventor: Charles W.Phillips, 2825 Newport Blvd, Costa Mesa, Calif.

[22] Filed: Jan. 19, 1972 211 App]. No.; 219,101

[52] U.S. Cl. 73/187, 73/431 [51] Int. Cl G0lc 21/10 [58] Field ofSearch 73/187, 431

[56] 1 References Cited UNITED STATES PATENTS 1451 Aug. 28, 19733,531,988 10/1970 Casanietal. 73/187 Primary Examiner-Donald O. WoodielAttorney-Harvey C. Nienow et a1.

[ ABSTRACT The present invention relates to a speed indicator orknotmeter, for indicating the speed of a boat; and

more particularly, relates to a knotmeter sending unit" that may beeasily and quickly withdrawn from and inserted through the hull of aboat.

The ease with which the sending unit may be handled encouragespreyentive maintenance, and facilitates repair when this is necessary.

13 Claims, 6 Drawing Figures Patented Aug. 28, 1973 3,754,441

2 Sheets-Sheet l 2 SheetsSheet 2 FIG.4

KNOTME'IER BACKGROUND -knotmeter, since a knot is a nautical mile perhour. Such a knotmeter usually comprises two compo,- nents; anindicating meter" positioned in front of the pilot, and a sending unitthat is affixed to the boat below the water line.

There are numerous types of knotmeters; i.e., wand type, thermal type,water-pressure type; but, in the most commonly used types, theunderwater sending unit usually comprises a rotatable active elementincorporating means such as vanes, a propeller, or the like that rotatesat a speed corresponding to the water flow pattern produced by themovingboat. The rotatable active element of the sending unit is preferablyplaced in an underwater location, where it is exposed to a relativelysmooth uninterrupted laminar" water flow as the boat moves through thewater. Preferred positions for the sendingunit are vertically throughthe bottom of the boat, or horizontally, throughthe boat's keel;preferably being positioned an appreciable distance away from otherunderwater protrusions.

The underwater sending unit may be connected; to

the indicating meter, in a number ofways, depending upon its design. Forexample, some knotmeters usea flexible connecting. cable that rotatesinv accordance with the rotation of the active element; and in this'wayactivates the indicating meter in the same manner as.

the speedometer of arr automobile, However, such a connecting cable hasthe disadvantage that bends,

kinks, and thelike tend to degrade'the operationof the Because of thedifficulty of removing and inserting .the sending unit, the sending unittends to be left in place unduly long; this being undesirable because ofOBJECTS AND DRAWINGS It is therefore the principal objective of thepresent 1 invention to provide an improved knotmeter.

It is another object of the present invention to provide an improvedknotmeter that practically eliminates the, ingress of water whileremoving or inserting the underwater sending unit.

Itis still another objective of the present invention to provide animproved knotmeter that permits the underwater sending unit to bequickly and easily removed and/or replaced. I

It is a further objective of the present invention to provide animproved knotmeter that has a housing designed. to prevent or minimizethe ingress of water.

It isa still further objective of the present invention toprovide animproved knotmeter that may be retrofitted onto existent boats.

It is a still further objective of the present invention to provide acapability for reducing and preventing marine fouling with minimumeffort.

Theattainment of theseobjects and others will berealized'fromthefollowing description taken in conjunction with, thedrawings of which:

FIG. 1 shows apictorial-view of the sending unit and itshousing in itsoutboard position, as viewed from the outside of the boat;

FIG. 2 shows a'pictorial-view of the sendinggunit and its housing in itsinboard position, as viewed-from the outside of the boat;

FIG. 3 shows a pictorial view of the sending unit housing in itsinboardposition, as viewed from the outside of the boat; thesending unit havingbeen removed from the housing;

FIG. 4 shows a pictorial view of the sending unit and inside of theboat; and

nance; and many boat owners feel that it is desirable to 1 remove theunderwater sending unit whenever the boat is not in use, to preventfouling when not in use.

One drawback of prior art knotmeters is the difficulty of removing andreplacing the underwater sendingunit; the prior art procedure being towithdraw. the sending unit into the boat, aNd to quickly plug or cap thehole from which the sending unit was removed. Unfortunately, even atbest, this prior art procedure permits an appreciable amount of watertoenter-the boat before the plug is properlypositioned; and if there isany difficulty in placing the plug, a large amount of water enters theboat.

A' similar water ingress situation results when the sending unit is tobe inserted.

FIG. 6 shows a pictorial view of the sending unit housing in its inboardposition, as viewed from the in-' side of the boat; the sending unithaving been removed from the housing.

SYNOPSIS INTRODUCTION The Bushing The present invention will beunderstood from FIG.

1, which shows the normal operative outboard position of the underwaterposition of a knotmeter as mounted on a boat; FIG. 1 showing theinstallation from the outside of the boat. In this illustration, theboat hull 11 is indicated to have a bushing 12 fixedly installed throughthe hull 11; the outer surface of the bushing flange 13 being flush withthe outer surface of the boat hull ll the bushing 12 and the bushingflange 13 being affixed to the boat hull 11 in any suitable manner (suchas screws, bolts, etc.). Bushing 12 has an integral tubular sleeve 14that extends through the boat hull l1, and terminates inside the boat;bushing sleeve 14 having a smooth accurately dimensioned inner surface15. For reasons that will be discussed later, bushing sleeve 14 will bedesignated as the outer sleeve 14." The Housing Positioned slidably inbushing- 12 is a cylindrical housing 17, shown in its outboard"position, in which it extends beyond the surface of the boat hull l1;and protrudes into the water. Housing 17 comprises a tubular innersleeve 18 whose outer surface 19 is smooth and accurately dimensions toform a sliding fit with the inner surface 15 of the outer sleeve 14; theproximal surface of the housing sleeve 18 and the bushing sleeve 14being designated as the housing/bushing interface."

As may be seen from FIG. 1, when the housing 17 is in its outboardposition, water may possibly leak into the boat through the abovediscussed housing/bushing interface; and in order to prevent such waterleakage, an inner seal such as an O-ring l6 is fitted into thebushing/housing interface, e.g., between the inner and outer sleeve 14and 18. Preferably, the inner O- ring 16 is fitted into a suitableperipheral groove in the housing sleeve 18.

Moreover, for reasons to be discussed later, an outer" seal such asouter O-ring 25 is similarly positioned near the end of the housingsleeve 18.

Housing 17 terminates in a housing flange 20 that is located inside theboat.

The Sending Unit The portion of housing sleeve 18 between the O-rings l6and 25 contains a window 21 through which may be seen the rotatableactive element 22 of the sending unit the active element 22 beingillustrated as comprising a plurality of vanes 23 that rotate asindicated by arrow 24 when the water flows past the boat hull 11 and thewindow 21. As the vanes 23 rotate, their rotation produces an electricalsignal that is transmitted over wires 26, the electrical signal beingapplied to the indicating meter, as discussed above.

For convenience, the proximal surfaces of the housing sleeve 18 and thesending unit 10 will be designated as the housing/sending unitinterface."

It will be noted, from FIG. 1, that when'the housing 17 is in itsoutboard position, water may leak into the boat through the window 21and the housing/sending unit interface. In order to prevent such waterleakage, a third seal such as an O-ring 27 is fitted into thehousing/sending unit interface. Preferably, this third O-ring 27 isfitted into a suitable peripheral groove in the sending unit 10. TheWater Flow Pattern It is preferable that the vanes 23 of the sendingunit 10 be exposed to a smooth laminar flow of water; and to accomplishthis result, a water fin 28 is used to smooth out any water turbulencebefore the turbulence reaches the vanes 23. The water fin 28 alsoprotects the housing against external damage when in the outboardposition. The uncut lower portion of the housing sleeve 18 protects thelower section of the vanes from water flow; and thus aids in theproduction of the water speed signals by removing the resistance to vanerotation that would be produced by water pressure on the back side ofthe vanes.

Operation of the Sending Unit The installation indicated in FIG. 1operates in such a way that as the water flows past the boat hull 11 itcauses rotation of the vanes 23; and those produce an electrical signalthat causes the indicating meter to show the boat speed.

As shown in FIG. 1, the scaling O-rings l6 and 27 act as seals thatprevent the leakage of water into the boat during the normal outboardpositioning of the housing 17.

Removal of the Sending Unit (l) It was previously pointed out that thesending unit must be frequently removed; and, in the past, a plug or acap was used to close the opening when this was done; but,unfortunately, the time interval between the removal of the sending unitand the installation of the plug or cap permitted an appreciable amountof water to enter the boat. Similarly, the removal of the plug or cap,and the insertion of the sending unit also permitted an appreciableamount of water to enter the boat.

The present invention solves this removal and insertion problem asfollows. When the sending unit is to be removed, the housing 17 and itscontained sending unit is pulled into its inboard position; as indicatedin FIG. 2.A suitable stopping pin 30 now abuts the bushing flange 13 toestablish the inboard position.

While the housing 17 is being moved from its outboard position to itsinboard position, O-rings l6 and 27 continue to prevent leakage of waterinto the boat; and when the housing 17 finally achieves its inboardposition as indicated in FIG. 2, the outer O-ring 25 now fits into thehousing/bushing interface; and thus prevents water leakage into theboat.

It should be noted that at this time, when the housing 17 is in itsinboard position, the outer end 29 of the housing 17 is flush with theboat hull 11; and thus permits an unimpeded movement of the boat throughthe water.

The next step in the removal of the sending unit 10 is the actualwithdrawing of the sending unit from the housing 17, while the housingis held in its inboard position the holding apparatus will be discussedlater. When this actual withdrawal has been accomplished, the bushing 12and the empty housing 17 appear as indicated in FIG. 3. It will be notedthat, at this time, when the housing 17 is in its inboard position,water leakage into the boat is prevented bythe action of the outersealing O-ring 25. Locked Outboard Position The operation of theinvention will be further understood from FIGS. 4, 5, and 6 these beingviews of the apparatus as seen from the inside of the boat. FIG. 4, forexample, shows the apparatuses it appears when the housing 17 is in anoutboard position and contains the sending unit 10. FIG. 4 shows thesending unit 10 to be fully inserted into the housing 17, which is inturn inserted into the bushing 12; water leakage being prevented by theO-rings as discussed previously.

In order to lock the various components in place for normal operation,and to prevent leakage of water it has been found desirable to uselocking means such as a locking stud 35 that traverses a first lockingaperture 36 (not visible in FIG. 4) of housing flange 20; and alsotraverses a second locking aperture 37 of a sending unit arm 38. Asuitable locking nut 40 assures that the various parts are locked intheir normal operating outboard positions.

Removal of the Sending Unit (II) When the sending unit l is to beremoved, the locking nut 40 is released (see FIG. 4); and the housing 17and its contained sending unit 10 are simultaneously pulled into theinboard position, as discussed previously and as shown in FIG. 5. Atthis time, the outer O- ring 25 now prevents leakage of water into theboat; and the stopping pin 30 holds the housing 17 from being completelydrawn into the boat.

In order to assure that the housing 17 and the bushing 12 retain thesealed inboard position relationship, locking stud 35 has a suitablelength, such that when the housing flange 20 is rotated away from thestud 35/aperture 36 alignment, (see FIG. 6), the housing flange 20cannot be inadvertently pushed forward to a position that would destroythe sealing relationship established by the outer O-ring 35. Thus, thehousing 17 and the outer O-ring 25 are held in a sealing relationshipwith the bushing 12, so that ingress of water is prevented.

ln order to actually remove the sending unit 10, it is now pulled out ofthe housing 17; the housing 17 still retaining its sealing relationshipwiththe bushing 12. As indicated in FIG. 6, the sending unit may now becompletely removed from the housing 17 to be cleaned, repaired, orreplaced, as may be necessary.

In order to prevent the inadvertent removal of the sending unit 10 fromthe housing 17 when the housing is not in its inboard position, FIG.shows the use of an L-shaped locking block 41 that coacts with thelocking stud 35 to hold together the sending unit and the housing flange20, because of the interrelation of the locking stud 35, the apertures36 and 37, and the locking block 41, the combination housing flange andthe sending unit 10 must be withdrawn to the inboard.

position simultaneously as a unit thus retaining the water sealingrelationship established by the various 0- rings. ()nly when the housingflange 20 has been pulled behind the end of the locking stud 35 can thesending unit 10 be removed; and at this time the housing 17 is rotatedto be held in place by the coaction of the stopping pin 30, the housingflange 20, and the locking stud Insertion of the Sending Unit When thesending unit is to be inserted, the above operations are perfonned inthe reverse order. The sending unit is first inserted into the dry emptyhousing 17 of FIG. 6; the end of thelocking stud 35 causing the rotatedhousing flange 20 to retain the housing/bushing sealing relationshipduring the sending unit replacement. Once the sending unit has beenproperly inserted into the housing 17, thesending unit 10 is rotated saycounterclockwise as indicated in FIG. 5 until its locking arm 38 engagesthe L-shaped locking block 41; and then the sending unit 10 and thehousing 17 are simultaneously rotated until the locking apertures 36 and37 are aligned with the locking stud'35. Now, the sending unit 10 andthe housing 17 are simultaneously pushed forward until they assume theoutboard position indicated in FIGS. 1 and 4. At this time, the lockingnut 40 may be affixed, to retain the desired operational outboardlocation of the various parts of the knotmeter structure.

It will be noted that none of the sealing O-rings are exposed torotational movement; acting only as static seals against water leakage.

SUMMARY The present invention has many advantages over prior art devicesof the kind. First of all, it facilitates the removal and the insertionof the knotmeters sending unit. Second, the insertion of the sendingunit is accomplished with absolutely no ingress of water into the boat.Third, the removal of the sending unit is achieved with minimal ingressof water into the boat. Fourth, the ease of removing and installing thesending unit encourages preventive maintenance and servicing. Fifth, theease of removal and installation of the sending unit facilitates repairswhen such are necessary. Sixth, suitable locking devices preventinadvertent moving of a component part. And finally, the disclosedapparatus is easily retrofitted onto an existent boat.

What is claimed is:

1. The combination comprising:

a housing adapted to have an inboard position relative to awater-restraining wall; first means for sealing against water leakagewhen said housing is in said inboard position; second sealing means forsealing against water leakage when said housing is in said outboardposition;

means for inserting a water-responsive device into said housing from thedry side of said wall when said housing is in the inboard position;

said first sealing means preventing ingress of water during saidinserting procedure;

means for removing a water-responsive device from said housing to thedry side of said wall when said housing is in said inboard position;

said first sealing means preventing ingress of water during said removalprocedure;

means for moving said housing to said outboard position for subjectingsaid device to said water.

2. The combination of claim 1 including a longitudinal window in thesidewall of said housing;

said window adapted to permit water to enter said housing when saidhousing is in said outboard position.

3. The combination of claim 2 wherein said first and said second sealingmeans comprise O-rings;

one O-ring being positioned to either side of said window.

4. The combination of claim 2 including a water responsive devicepositioned in said housing;

said device being exposed to water when said housing is in said outboardposition. 5. The combination of claim 2 wherein said device is thesending unit of a knotmeter.

6. The combination comprising; a housing adapted to have an inboardposition and an outboard position relative to th hull of a boat;

said housing having a longitudinal window through its sidewall, saidwindow being window adapted to permit water to enter said housing whensaid housing is in said outboard position;

a bushing fixedly positioned in said hull, said bushing being adapted topermit said housing to assume said inboard and said outboard positions;

first means for sealing the housing/bushing interface against waterleakage when said housing is in said inboard position;

second means for sealing the housing/bushing interface against waterleakage when said housing is in said outboard position;

a water responsive device positioned in said housing;

said device being exposed to water when said housing is in said outboardposition;

means for sealing said housing/device interface against water leakage;

means for removing said water-responsive device from said housing in theinterior of said boat when said housing is in said inboard position;

said first sealing means preventing ingress of water into said boatduring said removal procedure;

means for inserting such a water-responsive device into said housingfrom the interior of said boat when said housing is in said inboardposition;

said first sealing means preventing ingress of water into said boatduring said inserting procedure.

7. The combination of claim 6 wherein said water responsive device isthe sending unit of a knotmeter.

8. The combination comprising:

a housing adapted to have an inboard position and an outboard positionrelative to the hull of a boat; said housing having a window adapted topermit water to enter said housing when said housing is in said outboardposition;

said housing having a tubular sleeve adapted to permit said housing toassume said inboard position and said outboard position;

a bushing fixedly position through said boat-hull, said bushing having atubular sleeve adapted to encircle said tubular sleeve of said housing;

said tubular sleeve of said housing being adapted to slidelongitudinally in said tubular sleeve of said bushing for permitted saidhousing to assume said inboard and said outboard positions;

means, comprising a stopping pin positioned at the end of said housing,for stopping said housing in said inboard position;

means for sealing the housing sleeve/bushing sleeve interface againstwater leakage when said housing is in said inboard position;

means for sealing the housing sleeve/bushing sleeve interface againstwater leakage when said housing is in said outboard position;

a knotmeter sending unit, having an active element,

positioned in said housing; said active element being positioned at saidwindow of said housing;

said active element of said sending unit being adapted to be exposed towater flow pattern when said housing is in said outboard position;

said sending unit being protected from water flow pattern when saidhousing is in said inboard position;

means for sealing said housing/sending unit interface against waterleakage.

9. The combination of claim 8 including means, comprising a flange onsaid housing, for locking said housing against being inadvertently movedfrom said inboard position to said outboard position.

10. The combination of claim 8 including means, comprising an armassociated with said sending unit, for preventing said sending unit frombeing inadvertently withdrawn from said housing when said housing is insaid outboard position.

11. The combination of claim 8 including means, comprising a water fin,for producing a laminar water flow pattern adjacent said window whensaid housing is in said outboard position.

12. The combination of claim 8 including means for protecting saidhousing against external damage when said housing is in said outboardposition.

13. The combination of claim 8 wherein said sealing means compriseO-rings.

1. The combination comprising: a housing adapted to have an inboardposition relative to a water-restraining wall; first means for sealingagainst water leakage when said housing is in said inboard position;second sealing means for sealing against water leakage when said housingis in said outboard position; means for inserting a water-responsivedevice into said housing from the dry side of said wall when saidhousing is in the inboard position; said first sealing means preventingingress of water during said inserting procedure; means for removing awater-responsive device from said housing to the dry side of said wallwhen said housing is in said inboard position; said first sealing meanspreventing ingress of water during said removal procedure; means formoving said housing to said outboard position for subjecting said deviceto said water.
 2. The combination of claim 1 including a longitudinalwindow in the sidewall of said housing; said window adapted to permitwater to enter said housing when said housing is in said outboardposition.
 3. The combination of claim 2 wherein said first and saidsecond sealing means comprise O-rings; one O-ring being positioned toeither side of said window.
 4. The combination of claim 2 including awater responsIve device positioned in said housing; said device beingexposed to water when said housing is in said outboard position.
 5. Thecombination of claim 2 wherein said device is the sending unit of aknotmeter.
 6. The combination comprising; a housing adapted to have aninboard position and an outboard position relative to th hull of a boat;said housing having a longitudinal window through its sidewall, saidwindow being window adapted to permit water to enter said housing whensaid housing is in said outboard position; a bushing fixedly positionedin said hull, said bushing being adapted to permit said housing toassume said inboard and said outboard positions; first means for sealingthe housing/bushing interface against water leakage when said housing isin said inboard position; second means for sealing the housing/bushinginterface against water leakage when said housing is in said outboardposition; a water responsive device positioned in said housing; saiddevice being exposed to water when said housing is in said outboardposition; means for sealing said housing/device interface against waterleakage; means for removing said water-responsive device from saidhousing in the interior of said boat when said housing is in saidinboard position; said first sealing means preventing ingress of waterinto said boat during said removal procedure; means for inserting such awater-responsive device into said housing from the interior of said boatwhen said housing is in said inboard position; said first sealing meanspreventing ingress of water into said boat during said insertingprocedure.
 7. The combination of claim 6 wherein said water responsivedevice is the sending unit of a knotmeter.
 8. The combinationcomprising: a housing adapted to have an inboard position and anoutboard position relative to the hull of a boat; said housing having awindow adapted to permit water to enter said housing when said housingis in said outboard position; said housing having a tubular sleeveadapted to permit said housing to assume said inboard position and saidoutboard position; a bushing fixedly position through said boat-hull,said bushing having a tubular sleeve adapted to encircle said tubularsleeve of said housing; said tubular sleeve of said housing beingadapted to slide longitudinally in said tubular sleeve of said bushingfor permitted said housing to assume said inboard and said outboardpositions; means, comprising a stopping pin positioned at the end ofsaid housing, for stopping said housing in said inboard position; meansfor sealing the housing sleeve/bushing sleeve interface against waterleakage when said housing is in said inboard position; means for sealingthe housing sleeve/bushing sleeve interface against water leakage whensaid housing is in said outboard position; a knotmeter sending unit,having an active element, positioned in said housing; said activeelement being positioned at said window of said housing; said activeelement of said sending unit being adapted to be exposed to water flowpattern when said housing is in said outboard position; said sendingunit being protected from water flow pattern when said housing is insaid inboard position; means for sealing said housing/sending unitinterface against water leakage.
 9. The combination of claim 8 includingmeans, comprising a flange on said housing, for locking said housingagainst being inadvertently moved from said inboard position to saidoutboard position.
 10. The combination of claim 8 including means,comprising an arm associated with said sending unit, for preventing saidsending unit from being inadvertently withdrawn from said housing whensaid housing is in said outboard position.
 11. The combination of claim8 including means, comprising a water fin, for producing a laminar waterflow pattern adjacent said window when said housing is in said outboardposition.
 12. The combination of claim 8 including means for protectingsaid housing against external damage when said housing is in saidoutboard position.
 13. The combination of claim 8 wherein said sealingmeans comprise O-rings.